First hints for a correlation between amplification of the Int-2 gene and infection with human papillomavirus in head and neck squamous cell carcinomas

Epidemiology of human papillomavirus-related head and neck cancer

Human papillomavirus (HPV) is now recognized to cause a subset of head and neck squamous cell carcinomas (HNSCC). Although excessive tobacco and alcohol use continue to be important risk factors for HNSCC, epidemiologic studies suggest that more than 25% of HNSCC are now caused by HPV. The incidence of HPV-related HNSCC is increasing, highlighting the need to understand the oral HPV infections causing these cancers. This article reviews the evidence for a causal association between HPV and HNSCC, examines the changing epidemiologic trends of HNSCC, and discusses what is currently known about oral HPV infection, natural history, and transmission.

Basaloid in contrast to nonbasaloid head and neck squamous cell carcinomas display aberrations especially in cell cycle control genes

BACKGROUND

At present, the differences between head and neck basaloid squamous cell carcinoma (BSCC) and nonbasaloid squamous cell carcinoma (SCC) are mostly on the basis of histologic and immunohistologic findings.

METHODS

In this study, we investigated 8 BSCCs and 59 SCCs for loss of heterozygosity (LOH) at chromosomes 5q, 9p, 9q, 10q, 11q, 13p, 17p, and 18q. In addition, we analyzed p16, PTEN, and CCND1 (cyclin D1) and investigated the HPV status. Immunohistochemically, the expression of MIB-1, p16, p53, and cyclin D1 was determined.

RESULTS

Aberrations in the BSCCs were especially frequent at 9p and in the CCND1 gene. In contrast, alterations at 10q occurred almost exclusively in conventional SCCs. Obvious differences could be determined concerning the HPV status: HPV-DNA was detected in all BSCCs but only in 17% of conventional SCCs.

CONCLUSIONS

Although the number of investigated BSCCs is rather low and did not allow statistical conclusions, our results focus on certain differences between the molecular pathogenesis of BSCCs and SCCs.

The supplementary diagnostic power of selected immunohistochemical, molecular genetic and infective parameters in epithelial hyperplastic laryngeal lesions

OBJECTIVES

MIB-1 and p53 protein expression, loss of heterozygosity (LOH), microsatellite instability (MSI) of di- and mononucleotide repeats, and HPV status were tested for their potential to characterize different stages of epithelial hyperplastic laryngeal lesions (EHLL).

METHODS

Thirty-two EHLL were reclassified according to the Ljubljana classification into simple (SH), abnormal (AbH), atypical hyperplasia (AtH) and carcinoma in situ, and investigated by immunohistochemical methods, PCR and direct sequencing analysis.

RESULTS

MIB-1 increased with progressive grades of EHLL, whereas p53 protein expression was distinctive only between SH and AbH. LOH showed increasing frequency with grades of the lesions, but the distribution of altered loci (9p, 9q, 10q, 11q, 17p) was not qualified to differentiate between the stages. MSI was detected in SH, AbH and AtH without clear correlation to histopathological grading. HPV infection occurred mostly in SH and AbH (both: 66.7%).

CONCLUSION

MIB-1 labeling and allelic loss could assist histopathological diagnosis in the entire spectrum of EHLL, whereas the MSI results point to a genetic instability of the laryngeal mucosa in general and are therefore not helpful in the distinction of different stages of EHLL. However, future molecular genetic analyses should consider more late events of laryngeal carcinogenesis to improve their diagnostic potential. Furthermore, our results indicate that nonrisky and risky EHLL could probably be caused by different exogenous factors.

Minimal expression of the proto-oncogene int-2 encoded protein in a series of colorectal carcinomas

BACKGROUND

Int-2 (fibroblast growth factor-3) is a gene that belongs to the fibroblast growth factor gene family. It has been implicated in the carcinogenesis of several types of cancer, including esophageal squamous cell carcinoma, breast, head, and neck and lung carcinomas; but no firm data on its biological activity regarding neoplasms arising from the glandular epithelia of the gastrointestinal tract exists.

METHODS

In the present immunohistochemical study, we investigated the presence of int-2 encoded protein in a panel of 80 cases of colon carcinoma of various stages, grades and sizes. A sheep antihuman int-2 antibody was applied to paraffin-embedded tissue sections from the tumor samples. The percentage of int-2 immunostaining in the positively stained specimens was evaluated by image analysis.

RESULTS

Int-2 was positively detected in only four tumors (i.e. 5% of the cases examined). All immunopositive cases were moderately differentiated tumors; the adjacent mucosa did not express int-2 protein. The relevant patients were male.

CONCLUSION

These findings suggest that the role of int-2 in colorectal carcinogenesis is probably a limited one.

Oral squamous cell carcinoma; from an hypothesis about a virus, to concern about possible sexual transmission

Nearly two decades ago, we produced the first evidence for the presence of viral nucleic acids in oral squamous cell carcinoma (OSCC) tissues, hypothesising that there may be a viral involvement in at least some OSCC. Subsequently, human papillomaviruses (HPV) in particular have been implicated in OSCC. Antibody responses to HPV are seen and HPV-DNA detected in tumors by us and many others, the virus being mainly HPV-16, the genotype associated with ano-genital cancer. HPV are seen by in situ hybridisation only in tumour and premalignant tissue but not in surrounding normal mucosa suggesting HPV has a causal relationship. HPV may also be integrated in the host genome, further suggesting a causal role. Studies of patients with OSCC have suggested possible sexual transmission of HPV. Recent studies have indicated that HPV may be aetiologically important particularly in some types of oropharyngeal cancer, at least in tonsillar carcinogenesis, and may represent an alternative pathway in carcinogenesis to the established factors of tobacco and alcohol. We have come a very long way in the two decades since our first suggestion of a viral aetiopathogenesis was greeted with incredulity, and data from on-going studies by the International Agency for Research on Cancer, Johns Hopkins Oncology Center and others are eagerly awaited.